I think most of my friends who live in the UK don't live in London, but I know you might very well have friends or relatives who do. I hope your friends and families are safe and accounted for. My prayers are very much with you all.
I think what worries me the most, aside from wondering whether my friends are all right, is that to my knowledge there was no hint of this before today--no increased threat alerts, no talk on the news of increased 'chatter' among terrorists, nothing.
This is really not the way I like to be reminded of Alastor Moody's motto.